A load switch integrated circuit (IC) is an example of a power supply circuit. The load switch IC includes a switching element that controls whether power is supplied to a load or not. If the switching element is an N-channel metal oxide semiconductor (MOS) transistor, then a voltage boosting circuit is also provided generally. The voltage boosting circuit boosts an input voltage and supplies the boosted voltage to the gate of the N-channel MOS transistor. In this manner, it is possible to stabilize an on-resistance of the switching element regardless of the level of the input voltage. However, as the voltage boosting circuit operates, the consumption current of the load switch IC increases.
When the switching element is a P-channel MOS transistor, a voltage boosting circuit is not required, and thus, the consumption current is reduced. However, when the P-channel MOS transistor is used, the input voltage may decrease, and thereby, a switching operation of the load switch IC tends to become unstable.